14. Build it — Level 3

Project 1 · A page somebody actually uses · Build

Build it

What we are making: the device and the page, in that order.

The order

The sensor on the network, plainest possible page. One number, no styling. Get this working before anything else.
Check it from a phone, not from the laptop that programmed it.
Add the judgement — the word, using your threshold. Show the raw number next to it while you are testing.
Now make the page readable — that is the staple's style block, which you already changed in session 18. One big number, its units, its age.
Add the colour change and the self-refresh last.

💡 Tip

Start from a fresh copy of the staple, not from nothing. Every one of the five steps above is one or two slots. If you find yourself typing a whole program, stop — you are making more work than the project needs, and more places for it to break.

Do not add controls

This device is read, not operated. A page with no buttons is easier to use than one with three, and every control you add is something a visitor can get wrong. If you think you need a button, write down who presses it and why — and if you cannot, do not add it.

What you see	Why	What to do
The page loads on the laptop, not the phone	Different networks.	Both have to be on the same WiFi. Mobile data will not reach it.
It works in the lab, not in the place	Weak signal there.	Move it a metre, or switch to the board's own access point.
The reading is wild in the real place	Something that was not on your bench.	Sunlight, a draught, a door. Write it down — it is a real finding.
The page is slow	The sensor is being read on every request.	Read it every few seconds and remember the value.

Before you leave

The device serving a styled page with your judgement on it.
Checked from a phone, in the real place.
The IP address written down.

Challenge optional — only if you finish early

Leave your sensor running for the whole lesson and sketch a graph of what it saw.

13. The brief, and your plan